diff --git a/src/msw/listbox.cpp b/src/msw/listbox.cpp
index 9252783bed..1c7c0b5785 100644
--- a/src/msw/listbox.cpp
+++ b/src/msw/listbox.cpp
@@ -177,7 +177,8 @@ bool wxListBox::Create(wxWindow *parent,
         Append(choices[i]);
     }
 
-    // now we can compute our best size correctly, so do it if necessary
+    // now we can compute our best size correctly, so do it again
+    InvalidateBestSize();
     SetInitialSize(size);
 
     return true;